Field of the Invention
This invention is related to formation of tight, close fitting joints between two members such as panels of the type used in ready to assemble furniture or members used in stud walls and especially for attaching or joining wood based components. This invention is also related to male and female dovetail connectors or connector profiles.
Description of the Prior Art
In wood related products a balanced distribution of force with equal strength between mating portions of two members to be joined together is preferred. A dovetail slot that is routed along an entire edge of a panel, with a good fitting dovetail inserted along the entire length of the edge of the panel, has so much bearing surface between the two parts that the thinner wall on the outside of the sections can withstand a relatively significant amount of lateral pressure. Often referred to as a French dovetail, this type of connection is used widely in assembling drawer parts that are ten inches wide or less. However, the amount of resistance to insertion or removal of a well fitting through dovetail connection of this type is relatively significant and therefore much too cumbersome for use in connecting larger furniture components, wall sections or relatively large panels. These conventional dovetail configurations are therefore unsuited for applications such as ready to assembly, or knock down, furniture or for use in assembling stud walls or large panel members.
A very tight dry conventional sliding dovetail joint in wood products, with moisture changes that cause the wood products to swell and shrink at the manufacturing site and shipping the product around the world to many different climates has been virtually impossible in a production manufacturing environment. The instant invention will address and overcome these problems.
There are examples in the prior art of sliding dovetails that are made of rigid plastic and metal to make non-flexing connections in joining smaller parts. However, the friction created in larger panels would be so great it would be extremely difficult to assemble without special equipment, and are not designed to be disassembled. Semi-rigid plastic/metal sliding dovetails that flex so they can be inserted vertically into a dovetail slot are also easily flexed when torqueing pressures are applied to the connected members, so they are unsatisfactory in creating a solid non-flexing connection between members.
Straight dovetail slots are also used in hangers in which the dovetail slot has an open end, and a male member having a companion dovetail slot is inserted a female dovetail slot on the hanger. These dovetail slots are straight. These hangers are not used to join panel members or ready to assemble furniture because they do not provide a means for forming a tight, close fitting joint nor are they suitable for use in the panels because the panels would be weaken in the manner previously discussed.
Metal trapezoidal connectors are employed in some ready to assemble or knock down furniture, but these trapezoidal members protrude from the furniture components on which they are employed. There are not therefore suitable for forming tight, close fitting joints. Commercial trapezoidal connector are typically too large to be employed on ¾″ thick or slimline panels.
Other prior art connector configurations are employed for ready to assemble or knock-down furniture. Although these prior art connector configurations do allow panel members to be assembled together to form furniture, such as desks or tables, there are several problems with these prior art connector systems. First, these commercially available connector systems do not lend themselves to any degree of preassembly and shipping, and therefore a purchaser must first install the connector components in individual components. Installation of these conventional connectors therefore complicates the assembly process for the ultimate purchaser, especially those without mechanical ability. These conventional connector systems also require the use of tools for installation of the connectors or to interlock mating connectors. Disassembly, which is not even possible in some situations, only adds more problems, and can further deteriorate the structural integrity of ready to assembly products using conventional connector systems. Conventional connectors, normally shipped as loose piece items, may reduce assembly labor, but they lead to cumbersome final assembly that is time consuming and often leads to an unsatisfactory final product. A previous unsatisfactory experience will often cause customers to avoid subsequent purchases of ready to assembly furniture and other products.
Some prior art assemblies use adhesives to permanently glue RTA or ready to assembly products together, primarily because the other RTA fastening systems do not hold tightly together over long periods of time. These prior art RTA systems periodically usually need some retightening. Also the materials typical RTA connectors are made of pot metal or are cast and can break into pieces with repeated assembly. Therefore some users glue RTA components together during the first assembly.
Commercially available RTA cam lock connectors require a visible access point to tighten or release the connectors with a tool. These visible openings may have decorative covers, but either when these openings are visible or when covered they are aesthetically undesirable. The connector system of this invention does not require such accessible and visible openings.
The connector system according to this invention is designed to stay tight over long periods of use, and not need retightening. The connector system of the present invention is also designed to be easy to assemble and disassemble repeatedly, so taking it apart to move it to another location is easy. Most other RTA products are very labor intensive, and therefore most purchasers do not want the hassle of taking it apart and then reassembling.
U.S. Pat. No. 8,356,954 discloses a system for connecting modular components, especially suited for use with upholstered furniture instead of panels of the type used in case goods. A male connector having a conical or spherical surface protrudes from one modular component and is received within a keyhole slot that is formed in or attached to a second modular component. The keyhole slot can be formed by a router or other tool in a wooden frame member or in a separate piece that can be attached to the wooden frame member. The keyhole slot has a generally circular opening, through which the male connector can be inserted, and a narrower slot extending from the circular opening. A tapered or beveled surface extends from the bearing surface of the slot, which otherwise extends perpendicular to the face of the component in which the keyhole slot is formed. This tapered or beveled surface slopes between the portion of the slot joining the circular opening and an opposite closed end of the slot. This tapered or beveled surface can be formed by movement of a router or router bit transverse to the main surface of the component in which the keyhole slot is formed as the slot is formed. As the male connector moves along the slot toward the slot closed end, the male connector will be cinched tighter relative to the component containing the keyhole slot. Modular upholstered components, the thickness of which cannot be easily controlled, can thus be tightly secured by the connector system disclosed in U.S. Pat. No. 8,356,954.